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淬火钢磨削后具有一定的微观几何形状、显微硬度、以及残余应力。但在零件使用过程中,这种几何及物理机械性质均将发生变化。本文就 T7A 碳钢经不同时间磨损后的表面光洁度、显微硬度,以及残余应力分布规律的变化进行了初步的研究,试件先经热处理,并按一定规范磨削。研究结果指出,淬火钢经不同时间磨损后,其表面粗糙度降低;而显微硬度则随磨损时间的增长而增大,例如原始显微硬度为870公斤/毫米~2,经2小时磨损后增加到880公斤/毫米~2,经20小时磨损后则增加到975公斤/毫米~2。硬化程度也增加1—12%。但硬化层深度则无甚变化,处于0.17—0.20毫米。不管表面层原始残余应力是压应力还是拉应力,在磨损后就很快在表面层出现压应力,其值也是随着磨损时间的增长而增大,例如在2小时磨损后σ=-17公斤/毫米~2,而在20小时磨损后则增加到-65公斤/毫米~2。又应力梯度随磨损时间的增长而减小。应力变向点则随磨损时间的增长而增大。
Hardened steel after grinding with a certain degree of micro-geometry, microhardness, and residual stress. However, the use of the parts, the geometry and physical and mechanical properties will change. In this paper, the surface roughness, microhardness and residual stress distribution of T7A carbon steel after different wear cycles were studied. The specimens were heat-treated and grinded according to certain specifications. The results show that the surface roughness of hardened steel decreases with time, while the microhardness increases with the wear time, for example, the initial microhardness is 870 kg / mm ~ 2. After 2 hours of wear, Increased to 880 kg / mm ~ 2, increased to 975 kg / mm ~ 2 after 20 hours of wear. The degree of hardening is also increased by 1-12%. However, the depth of the hardened layer is not very different, at 0.17-0.20 mm. Regardless of whether the residual stress of the surface layer is compressive or tensile, compressive stress quickly appears on the surface layer after wear, and its value increases with increasing wear time, for example σ = -17 kg after 2 hours of wear / Mm ~ 2, but increased to -65 kg / mm ~ 2 after 20 hours of wear. Again, the stress gradient decreases with increasing wear time. Stress change point with wear time increases.